Hazel is a great tool for managing files and workflows. I have been using it to great effect for scanning in old photographs.
I use the Canon scanning software MP Navigator. I have it setup to automatically crop multiple photos and to save the resulting TIFFs into an "Add to iPhoto" folder.
On any TIFF file in this folder, Hazel runs an Automator script to convert it to a PNG file to save space. Then Hazel imports any PNGs into an iPhoto album.
As you can see, Automator first duplicates the file, converts it to a PNG, and then cleans up the name.
Hazel works on the TIFF, sending it to Automator to have the PNG created and then trashing it.
Now the newly created PNG can be imported into an iPhoto album and trashed.
This is a pretty simple example, but getting rid of the tedious aspects of these workflows is the kind of thing that makes Hazel and Automator such useful and versatile tools. You can download the Automator workflow here.